Automatic draft-regulator for steam-boilers



N M d L 2 Sheets-She t 1. 8) E. K. HUTCHISON. e

AUTDMATIG DRAFT REGULATOR FOR STEAM BOILERS.

Patented Jan. 11,1898.

mammal 2 Sheets-Sheet 2.

E. K. HUTCHISON.

AUTOMATIC DRAFT REGULATOR FOB. STEAM BOILERS. No. 597,375. Patented Jan. 11, 1898.

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UNITED STAT S EPHRAIM K. HUTCHISON,

PATENT Prion.

OF DENVER, COLORADO.

AUTOMATIC DRAFT-REGULATOR FOR STEAM-BOILERS.

SPECIFICATION forming part of Letters Patent No. 597,37 5, dated January 11, 1898.

Application filed June 11, 1896. Serial No. 595,135. (No model.)

To all whom it may concern.-

Be it known that LEPHRAIM K. HUTOHISON, a citizen of the United States, residing at Denver, in the county of Arapahoe and State of Colorado, have invented certain new and useful Improvements in Automatic Draft-Regulators for Steam-Boilers and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to automatic draftregulators for steam-boiler furnaces.

My object is to provide a draft-regulator of the class described which will more perfectly perform its functions by promptly responding to abnormal variations in pressure and immediately rectifying them, thereby saving the fireman much time and labor.

Having this object in view, the invention consists of certain improved features and novel combinations, as will appear more fully hereinafter.

In the accompanying drawings, Figure 1 is a side elevation of my complete invention Fig. 2, a plan view thereof; Fig. 8, a longitudinal section; Fig. 4, a side elevation of a boiler, showing the application of the device; Fig. 5, a cross seotion taken through the low-pressure valve, and Fig. 6 a similar view taken in front of a certain plunger.

a designates the casing or housing, which is provided with suitable brackets 1 and 2, by which the regulator may be secured in position. This casing is divided into three cylindrical compartments or chambers 3, 4, and 5, respectively, and is provided with a suitable gland 6 at one end thereof. The chambers 3 and 5 are steam-chambers, while that designated 4: is not. Chamber 3 is provided with admission and exhaust ports 7 and 8, respectively, .that communicate with chamber 5. The lower steam-chamber 5 has three drainpipes 9, 10, and 11, respectively, which aiford exhausts for the condensed or dead steam which would otherwise accumulate in the device.

A main piston 12, adapted for reciprocation in steam-chamber 8, is carried on the end of a piston-rod 13. The free extremity of this rod is provided with a coupling-head 14:, adapted for connection with the butterfly-damper 15 in the smoke-stack 16 by means of a pit-- man 17. This piston-rod moves through a partition 18, provided with a suitable stuffing-box, and carries two limiting-plungers 19 and 20, the former of which slides on a guide 21, which is provided with a limiting-abutment 22.

The piston-rod 23, working in the lower steam-chamber 5, carries three auxiliary pistons 2e, 25, and 26 and a releasing-plunger 27, which is provided with a stop 28, working in aslot in the partition between chambers 4 and 5, and has a lower upwardly-inclined face 29, being slotted longitudinally to provide arms 29. The piston 26 is somewhat larger than pistons 24 and 25, while piston 24: is provided with an exhaust-port 30, used to admit any existing steam to both faces of said piston and keep the same in equilibrium.

The numeral 31 designates a collar suitably secured within the chamber 5, and 31 a coilspring interposed between said collar and piston 26. The normal tendency of this spring is to keep the pistons pushed toward the left. The left extremity of piston-rod 23 is provided with an inclined abutment-face The numeral 33 designates the head of a plunger, which has an inclined abutment-face 34, on which the plunger 20 is adapted to ride, and is provided with a circular stem 35, having a port 36, and encircled by a spring 37, which tends to keep the plunger normally raised to prevent movement of plunger 20. The plunger 33 is straddled by arms 29 and is provided with trunnions 38, which press against the inclined faces 29 of the arms. The port in stem 35 permits any useless water or steam existing to pass out through the drain 11.

The low-pressure valve operates in a cylinder 39 and the high-pressure valve in a cylinder 40. These two cylinders are joined by a pipe 41, which is in communication with the delivery-pipe 42, that leads to the boiler. The low-pressure cylinder is connected to the steam-chamber 5 by a pipe 43, that leads to the space between pistons 25 and 26. The high-pressure cylinder 40 is connected to the casing a by a hollow coupling 44, that afiords communication between the cylinder and the steam-chamber 5. The rear face of this cylinder is connected to a vertical delivery-pipe 45, which communicates with the left end of the steam-chamber 3 by a delivery-port 46.

' The low and high pressure valves at? and 48 are provided'with stems i9 and 50, which are encircled by coil-springs 51 and 52, that abut on adjustable followers 53 and 545, that are screwed into double removable caps '55 and 56 and through which the stems pass.

Assuming that the boilerisdesigned to carry one hundred pounds pressure, it would I be. desirable to set the low-pressure valve at ninety-five pounds and the high-pressure valve at one hundred and five'pounds, al-

valve opens pipe 4:5. The tension on both of these valves may be regulated by turningthe plunger-53or Si by a suitable key.

The numeral 5r designates a short pivoted trip-leverprovidedwith an inclined abutment-face 58, adapted for engagement with abutment-face 32 and having one end pro jecting into'a notch59 in the valve 48. When the two abutment-faces come in contact, the

high-pressure valve is lifted. I

At there is shown a closure whichfits in and'forms part of the casing a.

mediately above the partition 18, and'it can be removed to allow access to the stuffing:

box in said partition. I V

., In the use of the term high pressure as applied to the valve 45 I am to he understood as meaning a valve which is adaptedito withstand a greater amount of pressurethan the valve 47, as said valve 48 is operated by the auxiliary piston.

The invention operates in the following manner: I have assumed that the boiler, the draft of which is governed by my regulator, is designed to blow at a pressure of one hundred pounds per square inch, in which case the low-pressure valve is adapted to lift at ninety-five pounds and the high-pressure valve at one hundred and five pounds. Let it be further assumed that the butterflydamper is open. (See Fig. 4.) The engagement of the plunger 19 with the lug 28 tends to keep the piston-rod 23 drawn toward the right and out of engagement with trip-lever 57, so that valve 48 is seated. hen the pressure rises above ninety-five pounds, the low pressure valve lifts, admitting steam through pipe 413 to the space between pistons 25 and 26. The latter piston being sufficiently larger in area than the former, the steam presses the piston-rod 23,toward the right.

This is imlever 57 andlilting the main ,pressuravalve The exhaust-port 18 is. also closed bypis- 5 ton 2a. The condensed steam in chamber 5 the main pressure-valve lifts, steam is again admitted to the left end of. chamber 3 and the main piston forcedtoward the right, again opening the damper. Just prior to the piston 12 reaching port 7 (through which and pipe 10 the dead steam in chamberSexhausts) plunger 20 rides on'plunger 33, depressing and passing the latter. Said plunger 33 then locks plunger 20. Immediately afterward is repeated.

The fluctuations in steam-pressure are thus automatically controlledian'd the best results attained.

Having thus described the invention, what is claimed as new is I 1. In an automatic draft-regulator, the'com plunger 19 engages with stop 23, thereby dis- I r 7 1 engaging trip-lever 57and allowing valve 48 tov reseat itself, When .thesteam-pressurc again rises above ninety-five pounds, the operation I bination with a steam-generator, of a draft damperya main cylinder, a main piston operating in said cylinder and operativelycone nected to the damper, an auxiliary cylinder,

anauxiliary piston 'operatiugin said cylinder,"a high-pressure valve governing the lion: of steam from the generator-to the main cyl-= in'der, a low-pressure valvegoverning the flow of steambetwcen the generator and the auxiliary cylinder, a steam connection to the main cylinder which is governed by the aux;- iliary piston, and mechanism operated by the auxiliary piston which is adapted to actuate the high-pressure valve.

2. In an automatic draft-regulator, the combination with a casing or housing provided with main and auxiliary steam-chambers and provided with a port which connects one end of the main steam-chamber with the auxiliary chamber, of a main piston movable in the main chamber and adapted for, actuating a damper, an auxiliary piston movable in the auxiliary chamber, means adaptedto actuate the auxiliary piston to prevent admission of steam through the port, a high-pressure valve adapted for actuation by the movement of the auxiliary piston to admit steam to the piston end of the main chamber, a low-pressure valve which is adapted to admit steam to the anxiliary chamber, and means normally adapted to prevent actuation of the high-pressure Valve by the auxiliary piston, substantially as described.

3. In an automatic draft-regulator, the combination with a casing or housing provided with main and auxiliary steam-chambers and having a port leading from one end of the main steam-chamber to the auxiliary chamber, of a main piston movable in the main chamber and adapted for actuating a damper, an auxiliary piston movable in the auxiliary chamber, a spring urging said auxiliary piston so as to normally prevent access of steam IIO through the port to the main chamber, means actuated by the main piston to lock the auxiliary piston, a high-pressure valve adapted to admit steam to the main chamber, and a low-pressure valve adapted to admit steam to the auxiliary chamber, the aforesaid auxiliary piston being adapted for engagement with the high-pressure valve to unseat the same when said auxiliary piston is disengaged by the movement of the main piston, substantially as described.

4. In an automatic draft-regulator, the combination with a casing provided with main and auxiliary steam-chambers which are in communication, of a main piston movable in the main chamber, a plunger connected to said main piston, an auxiliary piston movable in the auxiliary chamber and adapted to govern the flow of steam between the two said chambers, a piston-rod connected to said auxiliary piston and which has a stop adapted for engagement with the aforesaid plunger, a spring urging the auxiliary piston, a highpressure valve adapted to admit steam to the main chamber, a low-pressure valve adapted to admit steam to the auxiliary chamber, and

means actuated by the movement of the auxiliary piston to unseat the high-pressure valve.

5. In an automatic draft-regulator, the combination with a casing or housing provided with main and auxiliary steam-chambers, of a main piston movable in the main chamber, a piston-rod for said piston, a plunger carried by the piston-rod, the latter being adapted to actuate a damper, an auxiliary piston movable in the auxiliary chamber, a piston-rod therefor, a releasing-plunger carried by the latter piston, a second and spring-compressed plunger retracted by the movement of the releasing-plunger and adapted to engage with the first-named plunger, and means actuated by the movement of the auxiliary piston, whereby steam is admitted alternately on opposite sides of the main piston, substantially as described.

In testimony whereof I have signed this specification in the presence of two SllbSGlib'1 ing witnesses.

EPHRAIM K. HUTCHISON.

Witnesses:

O. K. TREGO, S. O. FLETCHER. 

